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3 Interactions found for:

allopurinol
Interactions Summary
  • 2 Major
  • 1 Moderate
  • 0 Minor
  • allopurinol

Drug Interactions

A total of 436 medications are known to interact with allopurinol. Add another medication to view potential interactions with this medication.

Common Interactions Checks

Drug and Food Interactions

Moderate
Allopurinol + Food

The following applies to the ingredients: Allopurinol

ADJUST DOSING INTERVAL: The tolerability of allopurinol may be improved by giving it after a meal. Additionally, when the dose is greater than 300 mg, dividing the total daily dose into smaller doses administered more often may be appropriate to help minimize gastrointestinal irritation.

MONITOR: Concomitant use of allopurinol with central nervous system (CNS) depressants, including alcohol, may potentiate adverse effects such as somnolence and sedation.

MANAGEMENT: To improve tolerability, some manufacturers suggest administering allopurinol after a meal. Additionally, if the daily dose is greater than 300 mg, administering allopurinol in divided doses may help reduce gastrointestinal intolerance. Patients should also be counseled to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until they know how the medication affects them.

References

  1. "Product Information. Allopurinol (Sandoz) (allopurinol)." Sandoz Pty Ltd (2024):
  2. "Product Information. Zyloric (allopurinol)." Aspen Pharma Trading Ltd (2021):
  3. "Product Information. Zyloprim (allopurinol)." AA Pharma Inc 248178 (2021):
  4. "Product Information. Allopurinol (allopurinol)." Actavis U.S. (Purepac Pharmaceutical Company) (2024):

Drug and Pregnancy Interactions

The following applies to the ingredients: Allopurinol

Safety has not been established.
-According to some authorities: This drug is only recommended for use during pregnancy when there are no safer alternatives and the benefit outweighs the risk.

AU TGA pregnancy category: B2
US FDA pregnancy category: Not assigned

Risk Summary: Based on findings in animals, this drug may cause fetal harm.

Comments:
-Animals exposed to this drug have shown negative developmental effects.
-Placental transfer of this drug and its metabolite have been reported.
-The available data on the use of this drug during pregnancy is limited and inconclusive. Pregnant women should be apprised of the potential risk to the fetus.
-This drug has been used widely for many years without apparent harmful effects.
-Infertility and impotence in men rarely occur during treatment with this drug, and studies have not confirmed an association with it.

Animal studies have failed to reveal evidence of fetotoxicity or teratogenicity. However, intraperitoneal administration of this drug in pregnant mice on gestation days 10 or 13 produced significant increases in fetal deaths and teratogenic effects (cleft palate, harelip, and digital defects). In another study, this drug after oral administration to pregnant rats during organogenesis caused embryonic resorptions, growth retardation, decreased fetal weight, and skeletal, liver, kidney, and brain abnormalities. A 2013 report analyzed 31 pregnancies exposed to this drug during the first trimester, finding that major birth defects and miscarriages were within the general population's range, but one child had severe defects. There is insufficient data in human pregnancy.

AU TGA pregnancy category B2: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

References

  1. "Product Information. Allosig (allopurinol)." Arrow Pharma Pty Ltd 18 March 2025 (2025):
  2. "Product Information. Zyloric (allopurinol)." Aspen Pharma Trading Ltd 19 Feb 2025 (2025):
  3. "Product Information. Aloprim (allopurinol)." Mylan Institutional LLC 2/2022 (2022):
  4. "Product Information. Zyloprim (allopurinol)." Casper Pharma LLC 9/2023 (2023):
  5. "Product Information. Allopurinol (allopurinol)." Leading Pharma, LLC 9/2024 (2024):

Drug and Breastfeeding Interactions

The following applies to the ingredients: Allopurinol

Breastfeeding is not recommended during use of this drug and for 1 week after the last dose.

Excreted into human milk: Yes

Comments:
-This drug and its active metabolite were detected in human milk.
-There was no report of effects of this drug on the nursing infant or on milk production.
-If the mother requires this drug, she does not have to stop nursing, but the nursing infant should be monitored for allergic reactions (such as rash) and undergo periodic CBC and differential blood counts.

References

  1. Bethesda (MD): National Institute of Child Health and Human Development (US) "Allopurinol - Drugs and Lactation Database (LactMed) https://www.ncbi.nlm.nih.gov/books/NBK501198/" (2025):
  2. "Product Information. Allosig (allopurinol)." Arrow Pharma Pty Ltd 18 March 2025 (2025):
  3. "Product Information. Zyloric (allopurinol)." Aspen Pharma Trading Ltd 19 Feb 2025 (2025):
  4. "Product Information. Aloprim (allopurinol)." Mylan Institutional LLC 2/2022 (2022):
  5. "Product Information. Zyloprim (allopurinol)." Casper Pharma LLC 9/2023 (2023):
  6. "Product Information. Allopurinol (allopurinol)." Leading Pharma, LLC 9/2024 (2024):

Therapeutic Duplication Warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

Switch to: Consumer Interactions

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.

Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

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